When defending the final section of the payload, you can stand just outside the spawn window on defense and shoot at the attackers - if they have no long range hitscan, they can't do much against you, since you can dodge the projectiles and step back to heal when needed. It just seems too much of an advantage compared to spawns on all other maps, especially considering how hard it is to push this map already. Basically this map *always* goes to 4th round unless one team gets completely stomped.